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形状记忆合金的奇异特性,已经受到人们的极大重视。特别是对镍钛形状记忆合金的研究和应用工作进展很快,但是该材料价格昂贵,限制了它的广泛应用。所以现在已开始注意研究和开发价格低廉的铜基形状记忆合金。可是该合金室温可塑性很差,至今报导的最大延伸率仅达15%,它与马氏体稳定化和抗过热能力差构成 Cu 基形状记忆合金三大难题。本文用正电子湮没多普勒展宽能谱测量和研究了经过特定温度淬火后的冷加工 Cu-25.24wt%Zn-3.83wt%Al 合金,发现室温加工压下量小时,几乎没有缺陷增殖,达到30%左右时,缺陷增殖到最大,但仍可继续冷轧,直到压下量为55%时才出现裂
The singularity of shape memory alloys has drawn great attention from people. In particular, nickel-titanium shape memory alloy research and application of work progressed rapidly, but the material is expensive, limiting its wide range of applications. So now we have begun to pay attention to the research and development of inexpensive copper-based shape memory alloys. However, the room temperature plasticity of the alloy is so poor that the maximum elongation reported up to now is as high as 15%. It has three major problems with Cu-based shape memory alloys that are poor in martensite stabilization and overheating resistance. In this paper, positron annihilation Doppler broadening spectrum was used to measure and study the cold-worked Cu-25.24wt% Zn-3.83wt% Al alloy after quenching at a certain temperature. It was found that there was almost no defect proliferation at room temperature processing with a small reduction of 30 % Or so, the defects proliferated to the maximum, but the cold rolling could continue until the reduction was 55%